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Original article

Video-assisted thoracoscopic clipping of patent ductusarteriosus: close to the gold standard and minimally invasivecompetitor of percutaneous techniquesEmmanuel Villa, Thierry Folliguet, Diego Magnano, Frederic Vanden Eynden,Emmanuel Le Bret and Francois Laborde

Objective To review our 12-year experience in video-

assisted thoracoscopic surgery (VATS) for patent ductus

arteriosus.

Methods VATS was performed in 743 patients. Three

groups were compared: 24 low-birth-weight infants

(LBWIs), 676 children between 2.5–25 kg and 43 boys

> 25 kg. A diameter of > 8 mm was the main

contraindication. For 85 consecutive patients, hospital stay

underwent cost analysis.

Results Median age was 1.6 years (range 5 days–33 years)

and median weight 9.0 kg (range 1.2–65 kg). Mortality was

nil. Median operative time was 20 min and hospital stay

2 days. Residual patency at discharge was 0% in LBWIs, 0.7%

in children, and 4.7% in boys (P U NS) and 0, 0.3, and 4.7% at

follow-up (P U 0.001). Persistent recurrent laryngeal nerve

dysfunction was recorded in 4.2% of LBWIs, 0.3% of children

yright © Italian Federation of Cardiology. Unauth

1558-2027 � 2006 Italian Federation of Cardiology

and 0% of boys (P U 0.012). Total mean cost was

s 5954 W 2110.

Conclusions The success rate of VATS clipping compares

favorably with the thoracotomic approach but without chest

wall trauma and it may have a very favorable cost-effective

therapeutic balance compared to transcatheter techniques.

J Cardiovasc Med 7:210–215 Q 2006 Italian Federation of

Cardiology.

Journal of Cardiovascular Medicine 2006, 7:210–215

Keywords: low-birth-weight infants, minimally invasive surgical procedures,patent ductus arteriosus, pediatrics, video-assisted thoracic surgery

Cardiac Pathology Department, Institut Mutualiste Montsouris, Paris, France

Correspondence and requests for reprints to Dr Emmanuel Villa, Cardiochirurgia,Fondazione Poliambulanza, Via Bissolati 57, 25124 Brescia, Italye-mail: emmanuel.villa@voila.fr

Received 28 January 2005 Revised 26 July 2005Accepted 1 August 2005

IntroductionMinimally invasive surgery has been one of the most

important surgical advances in recent years along with a

great development of techniques and materials for per-

cutaneous procedures aiming at treating heart diseases.

Nevertheless, division of a patent ductus arteriosus

(PDA) by means of posterolateral thoracotomy is still

considered the gold standard [1]. Actually, in the unre-

ported experience of congenital surgical teams and in

published series [2], the interruption of PDA via open

thoracotomy is a safe and reproducible surgical procedure

that provides very reliable results.

In recent years, closure by percutaneous techniques has

been increasingly adopted thanks to it being less inva-

sive, although burdened by some limitations related to

body weight and ductal morphology [1,3]. From the

surgical standpoint, advances also in equipment and

instruments have been attained and a net reduction in

morbidity has been obtained by means of minimally

invasive techniques. In the early 1990s, video-assisted

thoracoscopic surgery (VATS) began to be employed in

the pediatric field [4,5]. Although not yet widely

accepted, VATS for PDA closure is supposed to offer

the same results and safety standards as the traditional

approach having a reduced invasiveness like the

percutaneous approach.

This study aims at supporting this hypothesis reporting

our results and cost analysis on PDA closure with VATS

in order to compare them with data from conventional

treatment and those from catheter-based approaches.

MethodsPatientsReferring areas were the Paris regions, some hospitals

from northern France and from overseas domains. Pre-

sence of a clinically or instrumentally significant shunt

indicated closure of the arterial duct in low-birth-weight

neonates, whereas in older children persistent patency

was the indication. Pediatricians and pediatric cardiolo-

gists of referring hospitals chose the type of approach

(medical, surgical or percutaneous) for each patient. All

children referred to our institution for surgical strategy

were evaluated for VATS. The following criteria were

considered contraindications to VATS clipping: a duct

diameter of > 8 mm, previous thoracotomy, presence

of calcifications, active infection, or aneurysm. From

September 1991 to February 2004, a total of 794 patients

were referred to our institution for isolated arterial

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VATS clipping of patent ductus arteriosus Villa et al. 211

duct surgical treatment. VATS clipping was performed

in 743 of these cases and the series was retrospectively

analyzed. Of the remaining patients, 28 participated in a

study previously made at our institution for a robotically

assisted procedure [6], and the final 23 underwent a

standard thoracotomy due to contraindications to VATS.

Preoperative procedureStandard laboratory analysis and chest radiography were

performed primarily on an outpatient basis. Transtho-

racic echocardiography was systematically repeated on

the admission day for confirmation of the indication to

VATS. Angiography and cardiac catheterization were not

routinely performed if accurate anatomical and functional

definition was obtained by ultrasound. The degree of

pulmonary hypertension not allowing PDA closure by

VATS referred to the standard limits commonly accepted

[1]. The hospital governance committee evaluated the

procedures and informed approval from patients or

parents was obtained.

Surgical procedureTechnique and materials used have been reported in

previous studies and remained unchanged for the study

period with a few exceptions [4,7]. The principal steps

included two thoracotomy incisions for the introduction

of 5 mm trocars (L-shaped electrocautery and camera),

one smaller incision for direct nerve hook insertion (two

hooks for lung retraction, one for pleural reflection),

positioning of two 9 mm titanium clips through the

central incision after trocar removal, and pleural drainage

by one small-diameter wound drain catheter placed

through the same incision.

AnesthesiaAnesthesia was settled for a short-course operation. Pres-

sure monitoring, perfusion lines, and ventilation strategy

were employed as previously described [4,7]. Modifi-

cations in the pharmacological protocol were made in

recent years and new drugs introduced. The current

scheme is the following: propofol, sufentanil, atracurium

besylate for induction and sevoflurane and sufentanil

for maintenance.

Postoperative eventsEchocardiography was performed immediately after

VATS, either in the operating room, in the recovery

room, or in the intensive care unit depending on the

patient’s age and clinical status. If a persistent patency

was present, the patient was returned to the operating

room. In case of complete flow suppression, chest radi-

ography and extubation were then performed. Another

echocardiographic study was always conducted prior

to discharge.

All unfavorable events were recorded paying attention to

the following occurrences: residual shunt, VATS redo

opyright © Italian Federation of Cardiology. Unau

clipping, thoracotomy for bleeding or residual patency,

transfusion for bleeding, clinically detected transient

laryngeal nerve dysfunction (hoarseness, stridor, voice

changes), persistent laryngeal nerve dysfunction (ORL

confirmed), phrenic nerve injury, pneumothorax (if

requiring placement of a new drain), chylothorax, wound

infection, aneurysm formation, pulmonary artery steno-

sis, inadvertent clipping of another vessel, endarteritis/

endocarditis, or hemolysis. A complicated course was

defined if any of the cited morbid events occurred at

any moment after the operation. Intensive care unit and

surgical pediatric ward stay at our department were

considered postoperative stay. Continuation in neonatal

nursery due to the premature condition (lung immaturity,

weight deficit, etc.) was not considered as requiring

further stay due to surgical morbidity.

Referring pediatric cardiologists provided follow-up visits

on postoperative days 7 to 10 and after 6 months.

CostThe cost of hospitalization at our department (general

logistic, medical logistic, direct charges, meals, laundry,

sterilization) and the cost of the facility were determined

by a computer-based monitoring system of the function-

ing of our hospital. Consequently a daily mean charge was

obtained retrospectively. Technical consumption was

instead prospectively recorded using the scoring system

of the French National Health Organization. Data about

medical and administrative actions were collected and

linked. Every caring act was scored considering consump-

tion of medical, nursing, and technical resources (further

information available at www.le-pmsi.org).

Statistical analysisMeans were expressed � 1 SD; range was added if con-

sidered helpful to data interpretation. Patients were

divided into groups by body weight according to the

cut-off reported in the literature [8,9]. Pearson x2 test

or Fisher’s exact test when appropriate was used to

evaluate differences in the incidence of complications.

Statistical difference between data was achieved defining

the P significance according to the degrees of freedom.

Data were analyzed using a SPSS for Windows 11.5 (SPSS

Inc., Chicago, Illinois, USA).

ResultsMean age at surgery was 2.9 � 3.7 years ranging from

5 days to 33 years (Fig. 1). The male/female ratio was

0.6. The overall mean weight was 10.7 � 8.0 kg (range

1.2–65 kg). The subdivision into three groups was

made according to body weight and the composition of

the study population was the following: low-birth-

weight infants (LBWIs) 3%, children (between 2.5–

25 kg) 91%, boys (> 25 kg) 6% (Fig. 2). Mean weight

of LBWIs was 2.1 � 0.4 kg and the male/female ratio

was 0.8.

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212 Journal of Cardiovascular Medicine 2006, Vol 7 No 3

Fig. 1

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

Per

cen

t

>121211 10 9 8 7 6 5 4 3 2 10

Age (years)

Age distribution at video-assisted thoracoscopic surgery.

Table 1 Morbidity (743 patients)

Recurrent laryngeal nerve dysfunction 21 (2.8%)Transient 18 (2.4%)Persistent 3 (0.4%)

Thoracotomy 8 (1.1%)For bleeding 3 (0.4%)For residual shunt 5 (0.7%)

Pneumothorax 9 (1.2%)Transfusion 1 (0.1%)Chylothorax 4 (0.5%)Immediate residual patency 10 (1.3%)Residual patency at discharge 7 (0.9%)Residual patency at follow-up 7 (0.9%)

Associated cardiac anomalies were present in 4.2%

(n ¼ 31) but no defect required conventional treatment

by sternotomy or open thoracotomy when indication for

PDA closure was done. Conversely, 0.7% (n ¼ 5) of the

patients had previous cardiac surgery with a residual

ductal shunt detected in the postoperative course (three

ventricular septal defects, one atrial septal defect, one

anomalous pulmonary venous return).

Median operative time was 20 min (incision to skin glue

application). Postoperative stay ranged from 1 to 20 days

and the median hospital stay was 2 days. Direct home

discharge was made in 77.4% of cases (n ¼ 575), reflecting

a tendency to transfer, on the first postoperative day, to

secondary structures for a sort of protected convalescence

for patients where their home was a long distance away

from our hospital. Operative and 30-day mortality was nil.

Table 1 reports morbidity for all patients, whereas

Table 2 analyzes the three groups. Overall, unfavorable

yright © Italian Federation of Cardiology. Unauth

Fig. 2

Body weight groups. The low-birth-weight infant group is furthersubdivided.

events occurred in 9.0% of patients (n ¼ 67). Residual

patency of the ductus was detected immediately in 1.3%

of cases (n ¼ 10) and none in the LBWI group. In eight of

these patients, a second VATS clipping was performed,

whereas the remaining two were operated on by a limited

thoracotomy. The second procedure was successful in

both patients of the thoracotomy group but a residual

shunt remained in two of eight using the VATS strategy

(25%). These two known cases and another five tiny

persistent leaks that were not detected immediately after

the first operation, were documented at echocardiography

before discharge (0.9%). They were exiguous, clinically

tolerated, and only control visits were prescribed. At

6-month visits, all the PDAs known at discharge showed

no leak with the exception of one that underwent ligature

and clipping by minithoracotomy. Three other patients

had newly discovered shunts at follow-up (two of these

underwent closures with thoracotomic entry and one did

not undergo further procedure), for a final figure of 0.5%

(n ¼ 4) for overall late residual patency.

Chylothorax was managed conservatively with the excep-

tion of one patient who required thoracoscopic treatment.

In this group, mean postoperative stay was 10.0 � 6.7

days (range 6–20 days). Significant differences between

groups were recorded for the incidence of pneumothorax,

transfusion, thoracotomy, and complicated course.

Weight as risk factor for residual patency was observed

only at follow-up.

Finally, Table 3 reports the cost of a VATS clipping

operation at our institution in the last 85 patients (analysis

orized reproduction of this article is prohibited.

Table 2 Complications according to body weight groups

LBWIs Children Boys Pa

Recurrent laryngeal nerve dysfunctionTransient 2 (8.3%) 15 (2.2%) 1 (2.3%) NSPersistent 1 (4.2%) 2 (0.3%) 0 0.012

Pneumothorax 2 (8.3%) 7 (1.0%) 0 0.004Transfusion 1 (4.2%) 0 0 < 0.001Chylothorax 0 3 (0.4%) 1 (2.3%) NSThoracotomy 1 (4.2%) 4 (0.6%) 3 (7.0%) < 0.001Overall complicated course 8 (33.3%) 50 (7.4%) 9 (20.9%) < 0.001Immediate residual patency 0 9 (1.3%) 1 (2.3%) NSResidual patency at discharge 0 5 (0.7%) 2 (4.7%) NSResidual patency at follow-up 0 2 (3.2%) 2 (4.7%) 0.001

LBWIs, low-birth-weight infants. aP significance at 0.025.

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VATS clipping of patent ductus arteriosus Villa et al. 213

Table 3 Cost analysis of hospital stay (85 patients)a

Department stay 3517 � 1848Facility 214 � 112Technical consumption

Operating theater 975 � 239Anesthesia 994 � 234Imaging 100 � 51

Total cost 5800 � 211095% confidence interval 5351 � 6248

Costs are expressed in Euro. aanalysis refers to all consecutive patients treated inthe last 18 months. 2002 was the reference currency year.

Table 4 Overall cost analysis according to body weight groups

LBWIs Children Boys Pa

Total mean cost 6976 � 917 5957 � 2180 5579 � 1350 NS

Costs are expressed in Euro. LBWIs, low-birth-weight infants. aP significance at0.025.

was limited to the last 18 months owing to administrative

reasons and not to case selection) while Table 4 shows the

subdivision according to body weight.

DiscussionIn infancy closure of an isolated PDA removes the

hemodynamic burden of the left-to-right shunt. In older

children and boys suppression of the shunt is advised to

prevent infective endarteritis, pulmonary hypertension,

heart failure, aneurysm formation and pulmonary/

systemic thromboembolism [1,3]. PDA in premature

newborns presents some particularities [10] and surgery

is generally indicated in case of failure or contraindica-

tions to the pharmacological options [1].

After more than half a century of practice worldwide,

standard surgical approach has reached a high level of

safety and efficacy and it has been indicated as the gold

standard of treatment [2]. PDA may be simply ligated or

clipped; otherwise it may be sectioned and sutured. The

thoracotomy approach is still largely adopted owing to

the possibility of such an intervention at any age and to

the versatility offered to correct varied anatomical occur-

rences. However, it has resulted in some concerns about

long-term sequelae (rib deformity, scoliosis, shoulder

dysfunction) [11] besides postoperative pain, respiratory

dysfunction, and duration of hospital stay [12]. Today,

cosmetics and length of incision are questionably more

and more important, but is a fact that muscle cutting and

rib spreading are invasive parts of the standard surgical

approach.

At the beginning of the 1990s, we developed the pro-

cedure of VATS clipping to reduce the morbidity of open

thoracotomy. The series studied in this manuscript is the

largest reported to date. Instruments are introduced

through two trocars and only a supplemental incision

of a few millimeters is required to expose, dissect, and

opyright © Italian Federation of Cardiology. Unau

clip the PDA. Damage to the chest wall is reduced thanks

to the limited number of thoracotomies. Temperature

management, particularly relevant to younger patients, is

more facilitated with VATS than with thoracotomy, in the

absence of a wide thoracic cage opening and very short

operative time. The use of skin glue appeared be very

beneficial and no wound infections were recorded.

From our experience, VATS demonstrated a comparable

level of efficacy and a low level of morbidity to standard

techniques. Recurrent laryngeal nerve injury was noted

as a complication in 2.8% of our patients, whereas the

incidence with standard PDA ligation is reported to be

4.2% by Fan et al. [13]. Symptoms attributable to vocal

cord paralysis regressed in most of our cases and only

0.4% had long-lasting dysfunction, the cause being prob-

ably the trauma induced by traction or by electrocautery.

The incidence of long-lasting laryngeal nerve dysfunc-

tion in LBWIs was significantly higher (4.2%, P ¼ 0.012).

Zbar et al. [14] report a series of PDAs treated using open

thoracotomy and indicate an incidence of recurrent

laryngeal nerve injury of 22.7% in extremely low-weight

babies. This confirms the importance of the issue in

premature neonates and why the decreased incidence

achieved with VATS by improved vision from the video

camera is significant.

Conversion to thoracotomy for bleeding was necessary in

very few cases (three patients). Overall, thoracotomy was

required in 1.1% of patients: in addition to the three

previously mentioned, it was performed in five for diffi-

cult closure of the ductus (two immediate and three

residual shunts). Other authors report a number of

unplanned thoracotomies ranging from 1 to 7% in mixed

patient populations [15,16]. In our study, heavier patients

were found to be at risk of conversion. Therefore, a careful

echocardiographic evaluation of the size and anatomy of

the ductus is essential to adequately select patients for

VATS in order to minimize the incidence of conversion

and to manage larger PDA directly by thoracotomy.

Different issues are involved when caring for premature

and/or small babies. We did not have formal inferior

weight limit for VATS, but our patient recruitment was

influenced by the absence of a neonatal intensive care

unit in our hospital. Therefore, our VATS experience in

LBWIs is still limited, even though smaller instruments

and other strategies are under consideration [17,18].

Echo-Doppler studies have detected flow in clinically

silent ducts that have been only ligated [19]. Con-

sequently, because we were not dividing the ductus,

we always performed a double echographic check during

the hospital stay. Our protocol has allowed detecting

1.3% of incomplete closures. Each of these patients

underwent additional surgery and the second procedure

was unsuccessful in one-quarter of patients re-operated

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214 Journal of Cardiovascular Medicine 2006, Vol 7 No 3

using VATS. Therefore, it seems wise to remedy with

open surgery in the event that the first VATS operation

fails. This would allow shortcomings in clip size, ana-

tomic anomalies and difficult visualization to be more

easily overcome. Heavier patients require greater care

because of thicker duct walls. Indeed, residual patency at

follow-up (total incidence 0.5%) was significantly associ-

ated with body weight > 25 kg, as was the overall inci-

dence of thoracotomy.

Interventional PDA closure is now available in many

cardiac centers and it seems to have a high level of

reproducibility. Only recently, however, after use of coils

and accumulation of sufficient experience, results have

been comparable to surgery. Intermediate (1-year)

residual shunt was present in 5% of patients enrolled

in the European Registry [20]. Immediate residual

patency, however, was 41% and it is unknown in how

much time complete occlusion occurs. Consequently

concerns about effective complete closure, repeat exam-

inations, duration of follow-up, and necessity of long-

term antibiotic prophylaxis exist [21]. Superseding the

Rashkind double umbrella PDA occluder, the Amplatzer

occluder is an alternative to coils in large ducts. All of

these devices, however, maintain disadvantages and

potential intraprocedural risks such as embolization of

the occluder and peripheral vascular injury. Intravascular

foreign corps may protrude creating iatrogenic pulmonary

or isthmic stenosis or may be responsible for thromboem-

bolic events, hemolysis, infection, aneurysm, or recana-

lization [1,3,21–23]. Cases of vocal cord paralysis have

also recently been attributed to closure by coils [24].

The VATS technique is safely applicable to cohorts of

patients younger and lighter than those generally treated

in cardiological series [20,25]. We successfully performed

clip closure in a wide range of body size and age with a

simple set of instruments. Further, in our study a high

degree of efficacy was demonstrated for duct diameters

up to 8 mm. Multiple coils, conversely, are usually

required for duct diameters ranging from 3 to 8 mm,

increasing the risk of complications.

Sedation and local anesthesia generally allow very short

hospital stays in interventional practice. We deem home

discharge the morning of the second day advisable to

assure a safe early postoperative course and we consider

this practice as having an acceptable cost. Although we

did not systematically survey pain or cosmetic evaluation

of scars after VATS, patients (when possible) and parents

have often reported satisfaction with the smooth and

rapid course of recovery.

No extensive cost-effectiveness comparisons of VATS

clipping versus open surgery or versus currently adopted

transcatheter techniques are available in the literature.

Prieto et al. [25] stated that coil occlusion is as effective as

yright © Italian Federation of Cardiology. Unauth

and less costly than conventional surgery. Their con-

clusions are principally based on the cost of postsurgical

stay while considering the presence of persistent leaks

clinically negligible. Regarding these issues, we estimate

that the thoracoscopic approach may favorably influence

the cost-effective therapeutic balance thanks to a shorter

inpatient hospital stay (compared with conventional

surgery) and less residual shunts (compared with transca-

theter procedure).

Our retrospective and single-center study has some

limitations. Transcatheter techniques are not a thera-

peutic option available at our hospital; direct comparison

with VATS was therefore not possible and data of

patients not referred to our institution were not available

for outcome analysis. As previously mentioned, the

cohort of LBWIs was small and results in this group

are not completely conclusive. Other limitations are

related to cost comparisons between different systems

and institutions because they are always something hazar-

dous. Nonetheless, this study records a long experience

of continuous practice ranging from neonates to adults. It

wishes to provide data for evaluation of VATS in con-

genital practice and for indirect comparison with percu-

taneous techniques. Interest in VATS is growing

worldwide [16,18,26–28].

In conclusion, VATS clipping for PDA is a safe procedure

close to the efficacy of the gold standard thoracotomic

closure. This technique has been pioneered in the field of

less invasive congenital cardiac surgery and can be a valid

competitor of transcatheter procedures. With correct pre-

operative evaluation, VATS clipping may be performed in

all ductus diameters < 9 mm, but experience in LBWIs is

limited. The technique requires minimal operating time

and avoids morbidity related to chest wall trauma, percu-

taneous vascular access and intravascular foreign bodies.

References1 Benson LN, Cowan KN. The arterial duct: its persistence and its patency.

In: Anderson RH, Baker EJ, Macartney FJ, Rigby ML, Shinebourne EA,Tynan M, editors. Paediatric cardiology, 2nd ed. London: ChurchillLivingstone; 2002, pp. 1405–1459.

2 Mavroudis C, Backer CL, Gevitz M. Forty-six years of patent ductusarteriosus division at Children’s Memorial Hospital of Chicago. Standardsfor comparison. Ann Surg 1994; 220:402–409.

3 Therrien J, Connelly MS, Webb GD. Patent ductus arteriosus. Curr TreatOptions Cardiovasc Med 1999; 1:341–346.

4 Laborde F, Noirhomme P, Karam J, Batisse A, Bourel P, Saint Maurice O. Anew video-assisted thoracoscopic surgical technique for interruption ofpatent ductus arteriosus in infants and children. J Thorac Cardiovasc Surg1993; 105:278–280.

5 Burke RP, Wernovsky G, van der Velde M, Hansen D, Castaneda AR.Video-assisted thoracoscopic surgery for congenital heart disease.J Thorac Cardiovasc Surg 1995; 109:499–508.

6 Le Bret E, Papadatos S, Folliguet T, Carbognani D, Petrie J, Aggoun Y, et al.Interruption of patent ductus arteriosus in children: robotically assistedversus videothoracoscopic surgery. J Thorac Cardiovasc Surg 2002;123:973–976.

7 Laborde F, Folliguet TA, Etienne PY, Carbognani D, Batisse A, Petrie J.Video-thoracoscopic surgical interruption of patent ductus arteriosus.Routine experience in 332 pediatric cases. Eur J Cardiothorac Surg 1997;11:1052–1055.

orized reproduction of this article is prohibited.

C

VATS clipping of patent ductus arteriosus Villa et al. 215

8 Backer CL, Mavroudis C. Congenital Heart Surgery Nomenclature andDatabase Project: patent ductus arteriosus, coarctation of the aorta,interrupted aortic arch. Ann Thorac Surg 2000; 69(Suppl):S298–S307.

9 Burke RP, Jacobs JP, Cheng W, Trento A, Fontana GP. Video-assistedthoracoscopic surgery for patent ductus arteriosus in low birth weightneonates and infants. Pediatrics 1999; 104(Pt 1):227–230.

10 Cassady G, Crouse DT, Kirklin JW, Strange MJ, Joiner CH, Godoy G, et al.A randomized, controlled trial of very early prophylactic ligation of theductus arteriosus in babies who weighed 1000 g or less at birth. N Engl JMed 1989; 320:1511–1516.

11 Seghaye MC, Grabitz R, Alzen G, Trommer F, Hornchen H, Messmer BJ,von Bernuth G. Thoracic sequelae after surgical closure of the patentductus arteriosus in premature infants. Acta Paediatr 1997; 86:213–216.

12 Landreneau RJ, Hazelrigg SR, Mack MJ, Dowling RD, Burke D, Gavlick J,et al. Postoperative pain-related morbidity: video-assisted thoracic surgeryversus thoracotomy. Ann Thorac Surg 1993; 56:1285–1289.

13 Fan LL, Campbell DN, Clarke DR, Washington RL, Fix EJ, White CW.Paralyzed left vocal cord associated with ligation of patent ductusarteriosus. J Thorac Cardiovasc Surg 1989; 98:611–613.

14 Zbar RIS, Chen AH, Behrendt DM, Bell EF, Smith RJ. Incidence of vocalfold paralysis in infants undergoing ligation of patent ductus arteriosus. AnnThorac Surg 1996; 61:814–816.

15 Hines MH, Bensky AS, Hammond JW Jr, Pennington DG. Video-assistedthoracoscopic ligation of patent ductus arteriosus: safe and outpatient. AnnThorac Surg 1998; 66:853–859.

16 Nezafati MH, Mahmoodi E, Hashemian SH, Hamedanchi A. Video-assistedthoracoscopic surgical (VATS) closure of patent ductus arteriosus: reportof three-hundred cases. Heart Surg Forum 2002; 5:57–59.

17 Villa E, Mazzera E, Galetta D, Di Donato RM. Patent ductus arteriosus inneonates and new approaches. Ann Thorac Surg 2005; 79:1827–1828.

18 Hines MH, Raines KH, Payne RM, Covitz W, Cnota JF, Smith TE, et al.Video-assisted ductal ligation in premature infants. Ann Thorac Surg 2003;76:1417–1420.

19 Sorensen KE, Kristensen B, Hansen OK. Frequency of occurrence ofresidual ductal flow after surgical ligation by color-flow mapping. Am JCardiol 1991; 67:653–654.

20 Magee AG, Huggon IC, Seed PT, Qureshi SA, Tynan M, on behalf of theAssociation for European Cardiology. Transcatheter coil: occlusion of thearterial duct. Results of the European Registry. Eur Heart J 2001;22:1817–1821.

21 Sullivan ID. Patent arterial duct: when should it be closed? Arch Dis Child1998; 78:285–287.

22 Soares AM, Aiello VD, Andrade JL, Kajita LJ, Soares J Jr, Morhy SS, et al.Doppler flow evaluation can anticipate abnormal left lung perfusion aftertranscatheter closure of patent ductus arteriosus. Eur J Cardiol 2004;25:1927–1933.

23 Lozier JS, Cowley CG. Reactivity of the ductus arteriosus: implications fortranscatheter therapy. Catheter Cardiovasc Interv 2004; 61:268–270.

24 Liang CD, Ko SF, Huang SC, Niu CK. Vocal cord paralysis aftertranscatheter coil embolization of patent ductus arteriosus. Am Heart J2003; 146:367–371.

25 Prieto LP, DeCamillo DM, Konrad DJ, Scalet-Longworth L, Latson LA.Comparison of cost and clinical outcome between transcatheter coilocclusion and surgical closure of isolated patent ductus arteriosus.Pediatrics 1998; 101:1020–1024.

26 Kim BY, Choi HH, Park JB, Yu BS, Oh BS. Video assisted thoracoscopicligation of patent ductus arteriosus. Technique of sliding loop ligation.J Cardiovasc Surg (Torino) 2000; 41:69–72.

27 Vida VL, Rubino M, Bottio T, Padalino MA, Milanesi O, Pittarello D, StellinG. Thoracoscopic closure of the patent arterial duct. Cardiol Young 2004;14:164–167.

28 Georgeson KE, Robertson DJ. Minimally invasive surgery in the neonate:review of current evidence. Semin Perinatol 2004; 28:212–220.

opyright © Italian Federation of Cardiology. Unauthorized reproduction of this article is prohibited.